This invention relates to the working machine which externally controls a tool holder where a tool is mounted, and its communication method.
The automatic tool changer mechanism (ATC) in a machining center or the like changes various tools automatically. In this kind of work, a tool holder having a so called ATC shank is used, and the tool holder is generally installed to or removed from the spindle.
There is a request to control detection and position adjustment of the machining state of the tool in the tool holder using an external controller. A method to send infrared control signals to the tool holder is generally considered.
However, if the infrared control signal is used, position alignment and phase matching between the projector element and receiver element are necessary, and this kind of work is considerably cumbersome. Furthermore, this method uses optical lenses where coolant and chips are likely to attach, possibly causing malfunction and communication failure.
This invention aims to remove such trouble, aiming at providing a working machine which can send and receive signals between the tool holder and an external controller using radio communication, and a communication method.
Radio communication by means of electromagnetic waves is performed between the controller and a transmission and reception mechanism installed in the tool holder to which a tool is mounted. Here, the transmission and reception mechanism comprises an antenna which is wound at a distance around an electrically conductive part of the tool holder via a radio wave transparent material. For this reason, transmission and reception by means of radio communication are securely performed between the transmission and reception mechanism and the controller without effects on the tool holder which is made of iron, aluminum and other materials which absorb the radio wave.
During the radio communication procedure, when a predetermined working signal is supplied by the controller to the tool holder via an electromagnetic wave, a confirmation electromagnetic wave is sent back from the tool holder to the controller. This provides a secure detection means for the supply of the predetermined working signal to the tool holder, making it possible to avoid erroneous transmission and reception actions and to perform accurate radio communication control.
Further, when the transmission side sends a basic electromagnetic wave and an identifying signal wave simultaneously, the reception side performs a predetermined action corresponding to the signal wave only if both the basic electromagnetic wave and the signal wave are received. Therefore erroneous actions can be avoided and various actions can be performed at a high precision.
A radio wave transparent cover material is installed around the antenna. For this reason the antenna can be effectively protected against coolant and other foreign matter.
Further, the tool holder houses a starting switch circuit which makes it possible to supply electric energy from the power supply to the predetermined acting part inside the tool holder upon radio communication from the controller. This makes it possible to turn the power on during use of the tool holder only when necessary, making it possible to effectively cut waste electric energy through efficient use of the power supply. Here, the tool holder comprises a state display means driven by the starting switch circuit for direct monitor of the action state of the tool holder, thereby improving reliability.
The tool holder also comprises a correction head or measuring head, and the state of tool position adjustment by means of the correction head or the machining state of the workpiece by means of the measuring head can be automatically detected via the controller using radio communication.